Mastodons

The American mastodon was the last living member of the mastodon family, and lived around the Great Lakes, among many other places. The range was from Alaska to Honduras. The name came from it’s distinguishing feature, it’s teeth. Unlike the wooly mammoth, the mastodon’s teeth have nipple-like projections on the molars in order to suit it’s diet of leaves.

Paleontology Prime

Check out the album for pictures of a mastodon and on theories of their extinction.

The mastodons lived from 3.7 million years ago to 10,000 B.C., and there’s debate as to why they went extinct. One theory is that humans caused the extinction through hunting. Before man came to the continent, the only thing that could threaten adult-size mastodons would be American cave lions. The natural balance of predator and prey kept the numbers of both species in equilibrium. With humans present, suddenly more “predators” were killing mastodons and the balance was upset, even if only a few animals were killed each year.
Another theory was climate change. During the final few thousand years of the mastodon, the glacial ice sheet in North America was retreating. With the ice mass gone, weather changed. Large glaciers pull moisture out of the air and change natural weather patterns—the ice could be over a mile tall. With different temperatures and moistures, different plants bloomed. In order to still have the food supply they were adapted to, they had to move north along with the glacier. Eventually, there wasn’t enough food to keep their populations afloat, and they died out.
A third theory is that the lakes themselves locked them in the land that would become America, and that they died out when the food supply left. The Great Lakes formed when the retreating ice sheets pulled against the ground, and left giant gouges in the Earth. When they filled in, they became the lakes, and a very large and effective natural barrier. Very few mastodon fossils have been found north of the lakes, which gives credence to this theory.
What most likely happened is that all three of these theories described what happened. Ice sheets did retreat, whether did change, and humans did appear, and a mix of almost likely took them out.